System and method for an electrode seal assembly

ABSTRACT

A sealing system for isolating the environment inside a vitrification container from the outside environment comprises a vitrification container with a lid. The lid comprises two or more electrode seal assemblies through which two or more electrodes may be operatively positioned and extend down through the lid into the vitrification container. The electrodes may move axially up and down through the electrode seal assemblies or lock into place. The electrode seal assemblies each comprise a housing having two halves with recessed ring grooves. Sealing rings with a split may be placed into the grooves. Gas galleries may be machined or cast into the housing such that they are adjacent to the ring grooves. The gas galleries distribute gas onto the external faces of the sealing rings causing a change in pressure resulting in the sealing rings compressing onto the electrodes and forming a seal.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. patent application Ser. No.15/388,299, filed on Dec. 22, 2016, which claims priority to U.S.Provisional Patent Application No. 62/272,604, filed on Dec. 29, 2015,the entire contents of each of which are fully incorporated herein byreference.

COPYRIGHT NOTICE

Contained herein is material that is subject to copyright protection.The copyright owner has no objection to the facsimile reproduction byanyone of the patent document or the patent disclosure, as it appears inthe United States Patent and Trademark Office patent file or records,but otherwise reserves all rights to the copyright whatsoever. Thefollowing notice applies to the software, screenshots and data asdescribed below and in the drawings hereto and All Rights Reserved.

TECHNICAL FIELD

This disclosure relates generally to electrode seals and electrode sealassemblies for high temperature vitrification containers.

BACKGROUND

Vitrification methods involve the heating of waste material to betreated and a starter path which may comprise one or more conductivematerials (e.g. glass frit, graphite flake, silica, cullet) in avitrification chamber. The heating is effected by supplying current tothe vitrification container with the use of axially inserted electrodesfor the purpose of increasing the temperature of a starter path to thepoint where the adjacent material to be treated begins to melt. Once theheating is initiated and melting of the material begins, the moltenmaterial itself becomes conductive and can continue current conductionand heating. Application of power to the electrodes can continue untilthe material contained in the vitrification chamber is completelymelted. Electrodes are typically consumed by the melt in thevitrification container.

Gases may escape from the vitrification container between the electrodeand the lid and/or if the vitrification container is operated atnegative pressure cold air may be drawn in. Inability to maintain theatmosphere within the vitrification container leads to loss of heat, areduction in efficiency, and a potential loss of containment of gases inthe hood. The outer surface of the electrodes may be subject to erosionthrough oxidation caused by hot gases within the vitrification containerand heating of the electrodes which can reduce the current carryingcapacity of the electrodes. It is desirable to avoid leakage of gasesfrom the vitrification container as they can be harmful to theenvironment, workers, and equipment.

There is a need for electrode seal assemblies which are capable of atleast one of effecting seals under conditions of both positive andnegative pressures in the vitrification container, maintaining theenvironment in the vitrification container, allowing for axial movementof the electrodes, and preventing gases from being released. In someembodiments of electrode seal assemblies disclosed herein a seal iseffected using gas pressure resulting in pressure gradients greater thanthe pressure in the vitrification container.

So as to reduce the complexity and length of the Detailed Specification,Applicant(s) herein expressly incorporate(s) by reference all of thefollowing materials identified in each paragraph below. The incorporatedmaterials are not necessarily “prior art” and Applicant(s) expresslyreserve(s) the right to swear behind any of the incorporated materials.

Advanced Tritium System and Advanced Permeation System for Separation ofTritium from Radioactive Wastes and Reactor Water in Light WaterSystems, Ser. No. 62/239,660 filed Oct. 9, 2015, which is hereinincorporated by reference in its entirety.

GeoMelt Electrode Seal, Ser. No. 62/272,604 filed Dec. 29, 2015, whichis herein incorporated by reference in its entirety.

Ion Specific Media Removal from Vessel for Vitrification, Ser. No.15/012,101 filed Feb. 1, 2016, with a priority date of Feb. 1, 2015,which is herein incorporated by reference in its entirety.

Mobile Processing System for Hazardous and Radioactive Isotope Removal,Ser. No. 14/748,535 filed Jun. 24, 2015, with a priority date of Jun.24, 2014, which is herein incorporated by reference in its entirety.

Balanced Closed Loop Continuous Extraction Process for HydrogenIsotopes, Ser. No. 14/294,033, filed Jun. 2, 2014, with a priority dateof May 31, 2013, which is herein incorporated by reference in itsentirety.

Methods for Melting of Materials to be Treated, U.S. Pat. No. 7,211,038filed Mar. 25, 2001, with a priority date of Sep. 25, 2001, which isherein incorporated by reference in its entirety.

Methods for Melting of Materials to be Treated, U.S. Pat. No. 7,429,239filed Apr. 27, 2007, with a priority date of Sep. 25, 2001, which isherein incorporated by reference in its entirety.

In-Situ Vitrification of Waste Materials, U.S. Pat. No. 5,678,237 filedJun. 24, 1996, with a priority date of Jun. 24, 1996, which is hereinincorporated by reference in its entirety.

Vitrification of Waste with Continuous Filling and Sequential Melting,U.S. Pat. No. 6,283,908 filed May 4, 2000, with a priority date of May4, 2000, which is herein incorporated by reference in its entirety.

AVS Melting Process, U.S. Pat. No. 6,558,308 filed Apr. 25, 2002, with apriority date of May 7, 2001, which is herein incorporated by referencein its entirety.

Advanced Vitrification System 2, U.S. Pat. No. 6,941,878 filed Sep. 26,2003, with a priority date of Sep. 27, 2002, which is hereinincorporated by reference in its entirety.

Applicant(s) believe(s) that the material incorporated above is“non-essential” in accordance with 37 CFR 1.57, because it is referredto for purposes of indicating the background or illustrating the stateof the art. However, if the Examiner believes that any of theabove-incorporated material constitutes “essential material” within themeaning of 37 CFR 1.57(c)(1)-(3), applicant(s) will amend thespecification to expressly recite the essential material that isincorporated by reference as allowed by the applicable rules.

Aspects and applications presented here are described below in thedrawings and detailed description. Unless specifically noted, it isintended that the words and phrases in the specification and the claimsbe given their plain, ordinary, and accustomed meaning to those ofordinary skill in the applicable arts. The inventors are fully awarethat they can be their own lexicographers if desired. The inventorsexpressly elect, as their own lexicographers, to use only the plain andordinary meaning of terms in the specification and claims unless theyclearly state otherwise and then further, expressly set forth the“special” definition of that term and explain how it differs from theplain and ordinary meaning. Absent such clear statements of intent toapply a “special” definition, it is the inventors' intent and desirethat the simple, plain and ordinary meaning to the terms be applied tothe interpretation of the specification and claims.

The inventors are also aware of the normal precepts of English grammar.Thus, if a noun, term, or phrase is intended to be furthercharacterized, specified, or narrowed in some way, then such noun, term,or phrase will expressly include additional adjectives, descriptiveterms, or other modifiers in accordance with the normal precepts ofEnglish grammar. Absent the use of such adjectives, descriptive terms,or modifiers, it is the intent that such nouns, terms, or phrases begiven their plain, and ordinary English meaning to those skilled in theapplicable arts as set forth above.

Further, the inventors are fully informed of the standards andapplication of the special provisions of 35 U.S.C. § 112,116. Thus, theuse of the words “function,” “means” or “step” in the DetailedDescription or Description of the Drawings or claims is not intended tosomehow indicate a desire to invoke the special provisions of 35 U.S.C.§ 112, ¶6, to define the systems, methods, processes, and/or apparatusesdisclosed herein. To the contrary, if the provisions of 35 U.S.C. § 112,¶6 are sought to be invoked to define the embodiments, the claims willspecifically and expressly state the exact phrases “means for” or “stepfor, and will also recite the word “function” (i.e., will state “meansfor performing the function of . . . ”), without also reciting in suchphrases any structure, material or act in support of the function. Thus,even when the claims recite a “means for performing the function of . .. ” or “step for performing the function of . . . ”, if the claims alsorecite any structure, material or acts in support of that means or step,or that perform the recited function, then it is the clear intention ofthe inventors not to invoke the provisions of 35 U.S.C. § 112, ¶6.Moreover, even if the provisions of 35 U.S.C. § 112, ¶6 are invoked todefine the claimed embodiments, it is intended that the embodiments notbe limited only to the specific structure, material or acts that aredescribed in the preferred embodiments, but in addition, include any andall structures, materials or acts that perform the claimed function asdescribed in alternative embodiments or forms, or that are well knownpresent or later-developed, equivalent structures, material or acts forperforming the claimed function.

BRIEF DESCRIPTION OF THE FIGURES

A more complete understanding of the systems, methods, processes, and/orapparatuses disclosed herein may be derived by referring to the detaileddescription when considered in connection with the followingillustrative figures. In the figures, like-reference numbers refer tolike-elements or acts throughout the figures. The presently preferredembodiments are illustrated in the accompanying drawings, in which:

FIG. 1 is a block diagram showing the primary components in a typicalvitrification system.

FIG. 2 is an illustration of an electrode.

FIG. 3A is an isometric view of an embodiment of an electrode seal.

FIG. 3B is a top view of the electrode seal embodiment of FIG. 3A.

FIG. 3C is a front view of the electrode seal embodiment of FIG. 3A.

FIG. 4A is an isometric view of an embodiment of the seal assembly.

FIG. 4B is a top view of the electrode seal assembly embodiment of FIG.4A.

FIG. 4C is a front view of the electrode seal assembly embodiment ofFIG. 4A.

FIG. 4D is a bottom view of the electrode seal assembly embodiment ofFIG. 4A.

FIG. 4E is an isometric view of half of a clamshell style seal housingof the electrode seal assembly embodiment of FIG. 4A.

FIG. 4F is a cross section of the seal assembly detailing the interiorcomponents of the electrode seal assembly embodiment of FIG. 4A.

FIG. 4G is a cross section of the electrode seal assembly embodiment ofFIG. 4A without the graphite rod or electrode seals present.

FIG. 5A is an isometric view of an embodiment of an electrode sealassembly.

FIG. 5B depicts an exploded isometric view of the electrode sealassembly embodiment of FIG. 5A.

FIG. 5C depicts a cross section of the electrode seal assemblyembodiment of FIG. 5A.

FIG. 5D depicts an isometric view of a clamshell style seal housing ofthe electrode seal assembly embodiment of FIG. 5A.

FIG. 5E depicts a bottom view of the electrode seal assembly embodimentof FIG. 5A.

FIG. 6A is an isometric view of an embodiment of an electrode sealassembly.

FIG. 6B is a cross section of the electrode seal assembly embodiment ofFIG. 6A.

FIG. 7A is an isometric view of an embodiment of an electrode sealassembly.

FIG. 7B is an exploded view of the electrode seal assembly embodiment ofFIG. 7A.

FIG. 7C is a front facing cross section of the electrode seal assemblyembodiment of FIG. 7A.

FIG. 7D is an isometric cross-section the electrode seal assemblyembodiment of FIG. 7A.

FIG. 8A depicts an embodiment of the vitrification zone in thevitrification and off-gas treatment process embodiment of FIG. 1.

FIG. 8B depicts an embodiment of the off-gas pre-treatment zone in thevitrification and off-gas treatment process embodiment of FIG. 1.

FIG. 8C depicts an embodiment of the cooling zone in the vitrificationand off-gas treatment process embodiment of FIG. 1.

FIG. 8D depicts an embodiment of the off-gas wet scrubbing zone in thevitrification and off-gas treatment process embodiment of FIG. 1.

FIG. 8E depicts an embodiment of the off-gas final conditioning zone inthe vitrification and off-gas treatment process embodiment of FIG. 1.

FIG. 8F depicts an embodiment of the off-gas discharge zone in thevitrification and off-gas treatment process embodiment of FIG. 1.

Elements and acts in the figures are illustrated for simplicity and havenot necessarily been rendered according to any particular sequence orembodiment.

DETAILED DESCRIPTION

In the following description, and for the purposes of explanation,numerous specific details, process durations, and/or specific formulavalues are set forth in order to provide a thorough understanding of thevarious aspects of exemplary embodiments. It will be understood,however, by those skilled in the relevant arts, that the apparatus,systems, and methods herein may be practiced without these specificdetails, process durations, and/or specific formula values. It is to beunderstood that other embodiments may be utilized and structural andfunctional changes may be made without departing from the scope of theapparatus, systems, and methods herein. In other instances, knownstructures and devices are shown or discussed more generally in order toavoid obscuring the exemplary embodiments. In many cases, a descriptionof the operation is sufficient to enable one to implement the variousforms, particularly when the operation is to be implemented in software.It should be noted that there are many different and alternativeconfigurations, devices, and technologies to which the disclosedembodiments may be applied. The full scope of the embodiments is notlimited to the examples that are described below.

In the following examples of the illustrated embodiments, references aremade to the accompanying drawings which form a part hereof, and in whichis shown by way of illustration various embodiments in which thesystems, methods, processes, and/or apparatuses disclosed herein may bepracticed. It is to be understood that other embodiments may be utilizedand structural and functional changes may be made without departing fromthe scope.

Process Overview

FIG. 1 depicts different stages in an embodiment of a vitrificationprocess which include: the vitrification 100 (Zone 1), off-gaspre-treatment 120 (Zone 2), cooling (optional as needed) 130 (Zone 3),off-gas wet scrubbing 140 (Zone 4), off-gas final conditioning 150 (Zone5), and off-gas discharge 160 (Zone 6). Other embodiments may utilizedifferent zones and processes. Vitrification is used to destroy orimmobilize hazardous waste by exposure to high temperatures that resultsin the contaminants being eliminated or entrained within a glass matrix.The process reduces or eliminates pre-treatment requirements, increaseswaste load capacity, and reduces maintenance costs as compared to otherhazardous waste processing and storage methods. Some hazardous wasteprocessing and storage methods are only suitable for a single waste typeor classification whereas vitrification can be applied to a wider rangeof hazardous materials. Vitrified glass has a high waste loadingcapacity and is considered stable.

In some embodiments the vitrification process used is in-containervitrification (ICV™) In-container vitrification (ICV™) treatment issimilar to conventional vitrification methods. It differs in that theentire vitrification process and subsequent storage of the vitrificationprocess product occurs within the same container thus reducing equipmentand steps required in final processing. The container used in thevitrification process may be a sealed electric arc furnace, joule heatedmelter, or other type of sealed furnace or melter. The system in whichthe vitrification container is used is referred to herein as thevitrification containment system (VCS). The VCS comprises avitrification container, at least one electrode, and a lid for sealingthe top of the vitrification container. The lid, or hood, comprises oneor more lead-throughs, hereinafter referred to as electrode sealassemblies, through which the one or more electrodes are fed into thevitrification container. The electrode seal assemblies may provide atleast one of thermal and electrical insulation for the electrodes, insome embodiments. The electrode seal assemblies may provide pressure andgas/air flow isolation for the electrode from the hood environment, insome embodiments. The electrode seal assemblies may provide anatmospheric seal while under differential pressure conditions, in someembodiments.

Continuing with an embodiment description of FIG. 1, off-gases from thevitrification process may be pre-treated in an Off-Gas Pre-Treatmentprocess 120 (Zone 2). A Cooling process 130 (Zone 3) is an optional stepthat may be used in cases where the temperature of the off-gas may needto be lowered. The off-gases may contain substances considered harmfulto the environment. Off-Gas Wet Scrubbing 140 (Zone 4) may utilize awet-scrubber to decontaminate the off-gas, flue gas, or other gasescontaining various pollutants. After the Off-Gas Wet Scrubbing process140, the off-gas may proceed to further conditioning in the Off-GasFinal Conditioning process 150 (Zone 5) based on the outputrequirements, including to meet environmental release requirements. Thismay include moisture removal, further treatment of remaining impuritiesor particles, etc. Once the treatment is complete, the off-gas can bereleased via the Off-Gas Discharge 160 (Zone 6). The off-gas may eitherbe released to the environment if it meets regulations, reused as wasteheat in the process or a separate process, or it may be discharged forfurther processing.

Terminology

Vitrification Container—The vitrification container may refer to acontainer in which the electrode(s) are inserted and the vitrificationtakes place. In some embodiments, electrode seal assemblies are coupledto the lid of the vitrification container to facilitate insertion of theelectrode(s).

Electrode—An electrode may refer to an electrical conductor used to makecontact with a nonmetallic part of a circuit. The electrode(s) conductenergy within the vitrification container to facilitate vitrification ofthe materials within. An embodiment of an electrode is depicted in FIG.2. Electrodes are typically generic to various embodiments of electrodeseal assembly designs.

Electrode Seal Assembly (also referred to as Seal Assembly orLead-Through)—Electrode seal assembly may refer to a complete assemblycomprising the electrode seal housing, sealing ring(s), and any otherfasteners and gaskets that form each embodiment. Electrode sealassemblies for high temperature vitrification containers have a primarypurpose of preventing gases from escaping the treatment vessel and asecondary purpose of providing guides for electrode insertion into themelting environment. Any one or more components forming any embodimentof an electrode seal assembly may have one or more chamfered edges tofacilitate insertion of an electrode and to minimize potential forshavings to shear off the electrode.

Seal Housing—The term seal housing may refer to the one or more primarystructural components of an electrode seal assembly. The seal housingserves to contain the sealing rings and to couple to the vitrificationcontainer lid as insulation between the electrode(s) and otherconducting components.

Electrode Seal also referred to as Graphite Seal, Sealing Ring, orSeal—The terms may refer to the individual sealing rings and not to anentire electrode seal assembly. An embodiment of a sealing ring isdepicted in FIGS. 3A through 3C. The depicted sealing ring is usedthroughout the depicted electrode seal assembly embodiments; howeverother sealing ring embodiments may be utilized. In some embodiments thesealing ring may contain at least 95% carbon content.

Sealing Section—Sealing sections may refer to separate areas within aseal housing in which one or more sealing rings reside. Each sealingsection may comprise one or more sealing rings. Each seal housing maycomprise one or more sealing sections. The need for a sealing sectionembodiment is further described later in the disclosure.

Electrodes and Seals

FIG. 2 depicts an embodiment of an electrode 250. The length of theelectrode 250 is generally greater than the diameter. In someembodiments, one end of the electrode 250 is tapered 251. The taperedend 251 facilitates alignment of the electrode 250 during insertion intoan electrode seal assembly and vitrification container. One or moreelectrodes 250 may be inserted into an electrode seal assembly and fedinto the vitrification container as the melt deepens, maintaining theend of the electrodes 251 at or near the bottom of the melt area. Thisrequires a portion of the electrodes 250 to be extended above thevitrification container at the early stages in the melt process.

Long electrodes 250 are more likely to break due to increased momentarm; therefore the electrodes 250 in some embodiments may be threaded toallow shorter sections to be added incrementally. Typically, smallerelectrodes 250 may be male/female and larger electrodes 250 may befemale/female and attached with a double threaded male nipple. On theelectrodes 250, the male ends are typically fully threaded but thefemale ends can only be threaded to a minimum shell thickness. At thejoint between smaller diameter male/female electrode 250 segments thereis often a gap that is created by the threads.

Graphite electrodes are commonly used in electric arc furnaces due totheir excellent electrical and thermal conductivity, high temperaturestrength, and low thermal expansion. Graphite is the preferred electrodematerial; however, other materials are considered including bothconsumable and non-consumable electrode materials. While graphiteelectrodes are commonly used for vitrification, there are some aspectsthat can be problematic. A common problem with graphite electrodes 250are small shavings that occasionally shear off of the electrodes 250onto the top of the electrode seal assembly and vitrification chamber.These shavings may cause electric arc potential, with an embodimentsolution described later in this disclosure. Electrodes 250 may beconductive, heat resistant, and corrosion resistant.

FIGS. 3A through 3C depict different views of an embodiment of anelectrode seal 200, also referred to as “seal”, “sealing ring”, or“graphite seal”. The terms may refer to individual sealing rings and notto an entire electrode seal assembly. Each electrode seal assembly maycomprise one or more sealing rings. Sealing rings are typically genericto various embodiments of electrode seal assembly. In some embodimentsthe one or more sealing rings 200 may be composed of graphite. Graphitesealing rings 200 may be preferred due to graphite being heat resistant,oxidation resistant, wear resistant, and having a low coefficient offriction; however, other materials may be used. In embodiments utilizingmore than one sealing ring 200, each sealing ring 200 may be composed ofdifferent materials or they may all be composed of the same material.

In some embodiments the sealing rings 200 may be wrapped in a materialthat, when subjected to heat and pressure, forms a thick, stable, andpassivating oxide layer which protects the surface of the sealing ring200 from degradation. In some embodiments the sealing rings 200 arewrapped with a material that is austenite nickel-chromium based. In someembodiments one or more of the sealing rings 200 may be Inconel wrapped.In some embodiments the Inconel is spiral wrapped around the outercircumference of the sealing ring 200. Inconel increases resistance tocorrosion at high temperatures as well as rigidity. The sealing rings200 in some embodiments may be composed of a material that is rated forservice in extreme environments including extreme heat and pressure(e.g. graphite). In some embodiments utilizing more than one sealingring 200, one or more of the sealing rings 200 may be Inconel wrapped.

In some embodiments, the aforementioned gap that may be present betweenrod sections may be able to pass through the seal assembly withoutlosing the seal on the electrode, i.e. at least one sealing ring 200 orsealing section should be fully engaged around the electrode at anygiven time. For instance, if there are two sealing sections, theelectrode gap should be able to pass through one sealing section whilethe other is still fully engaged. The more sealing sections, the higherthe factor of safety.

The sealing rings 200 in some embodiments are manufactured with theinner ring edges chamfered 201 as shown in FIG. 3A; since the same forceis applied on a smaller internal surface 208 area, the higher pressureresults in an enhanced sealing effect. In some embodiments, the sealingrings 200 have a swept cut, or split, end 202 which allows them tocontract and tighten around the electrode under induced pressure on theexternal surface 207. One or more of the sealing rings 200 may have oneor both sides of the inner ring chamfered to facilitate motion of therod down through the seal housing and to reduce the incidence ofshavings shearing off the electrode. In some embodiments, only the topor the bottom edge of the sealing ring 200 internal surface 208 ischamfered.

Electrode Seal Assembly Embodiments

The following section discusses several electrode seal assemblyembodiments. The order of presentation does not imply order ofpreference. It should be clear that while each embodiment is discussedas a separate whole from the other embodiments that various aspects fromany one or more embodiments may be combined to form other embodimentsnot explicitly disclosed herein.

In some embodiments, sealing may be enhanced by a positive gas pressurecurtain barrier and/or a plurality of mechanical seals. In someembodiments utilizing a pressure seal the air or inert gases used toeffect the pressure seal may be one of heated or cooled depending on thematerial to be vitrified and other system variables. In some embodimentsutilizing a pressure seal one or more sensors, regulators, and/or valvesmay be used to monitor and control flow in the seal assemblies. In someembodiments, gases escaping past the seals may be aspirated forrecycling into the vitrification container.

In an example embodiment, a sealing system comprises two or moreelectrodes and a vitrification container. A lid is attached to thevitrification container to form a sealed vitrification container. Two ormore electrodes are operatively positioned through the lid and extenddown into the vitrification container. In this example embodiment, twoor more electrode seal assemblies are affixed to the lid. The two ormore electrode seal assemblies may provide at least one of thermal andelectrical insulation for the two or more electrodes, in someembodiments. The two or more electrode seal assemblies may provide a wayto isolate the environment external to the vitrification system from theconditions inside of the lid, or off-gas hood, while also allowing theelectrodes to penetrate and be moved into and out of the vitrificationzone. The two or more electrode seal assemblies each comprise a housingwherein the housing comprises of two halves and ring grooves recessedinto the housing. Sealing rings with a split may be placed into thegrooves wherein the placement results in external faces of the sealingrings being recessed into the ring grooves. The system also comprisesgas galleries that may be machined or cast into the housing such thatthey are adjacent to the two or more ring grooves. The gas galleriesdistribute gas equally onto the external faces of the sealing rings froman interior face of the ring grooves. The distributed gas causes achange in pressure resulting in the sealing rings compressing onto theelectrode and forming a seal.

FIGS. 4A through 4G depict an embodiment of an electrode seal assembly300.

FIG. 4A depicts an isometric view of an embodiment of an electrode sealassembly 300. The electrode seal assembly 300 comprises a seal housing310, housing gasket 350, two split gaskets 355, and one or more hosefittings 325 and 320. In some embodiments, such as the one depicted inFIGS. 4A through 4G, the seal housing 310 is split into two halves in a“clamshell” design. In some embodiments, the seal housing 310 may besplit into more sections. In some embodiments, the sections of the sealhousing 310 are identical. The clamshell design of the seal housing 310allows for easy maintenance and replacement. The sections of the sealhousing 310 may be fastened with fasteners. Split gaskets (not shown)may be placed between each section of the seal housing 310. In someembodiments the split gaskets are composed of graphite, or other thermaland/or electric insulating materials, or combinations thereof. In someembodiments the split gaskets may be comprised of a rope seal material,high temperature fiber, or other material rated for high heat (above500° C. in some embodiments) and that is capable of providing a seal toprevent leakage. In some embodiments one or more of the gaskets may beformed of graphite with a stainless steel inner core.

FIG. 4B depicts the top of the electrode seal assembly 300. The depictedbolt holes 364 may be used to secure the electrode seal assembly 300 tothe top of the vitrification container. In the depicted embodiment thereare four bolt holes 364, however the number of bolt holes 364 may varydependent on a number of factors such as size of the electrode sealassembly 300 and fastener type and size, to name a few. The hosefittings 325 and 320 may be used to supply and release pressure aroundthe seals using air or other inert gases.

FIG. 4C depicts a front view of the electrode seal assembly 300. In thedepicted embodiment the electrode seal assembly 300 is comprised of twoidentical seal housings 310. The two seal housings 310 are fastenedtogether using a number of fasteners, which may vary betweenembodiments. The electrode seal assembly 300 comprises a flange 362which rests on the top of the vitrification container. The flange 362provides holes 364 (FIG. 4D) through which the electrode seal assembly300 may be mounted to the vitrification container. A housing gasket 350may be positioned between the flange 362 and the vitrificationcontainer. The flange 362 of the seal housing 310 is fastened down tothe top lid of a vitrification container. In some embodiments, the sealhousing 310 may be comprised of ceramic, graphite, Macor™, CS-85, otherthermal and/or electric insulating materials, or combinations thereof.Other seal housing material may be used. The housing gasket 350 may becomprised of graphite with a stainless steel inner core in someembodiments.

FIG. 4D depicts a bottom view of the electrode seal assembly 300. In thedepicted embodiment, gas galleries 330 are drilled through the base ofthe electrode seal assembly 300. The depicted embodiment compriseseighteen evenly distributed vertical gas galleries 330; however otheramounts and configurations are possible. Gas galleries 330 are shown anddescribed in more detail in FIGS. 4F and 4G.

FIG. 4E depicts an isometric view of one half of the seal housing 310.The ring grooves 375 inside the seal housing 310 are designed to holdand secure the sealing rings 200 (FIGS. 4F and 3A-3C) in position. Inthe depicted embodiment there are four ring grooves 375 however otherembodiments may comprise other amounts. In some embodiments one or morering groove 375 may be sized to accommodate more than one sealing ring200. In some embodiments the ring grooves 375 comprise a pressure groove376 which allows gas flow around the sealing rings 200 (FIG. 4F) toeffect a pressure seal.

FIG. 4F is a cross-sectional view of the seal housing 310 with theelectrode 250 and sealing ring 200. The depicted embodiment 300 usespressurization to reinforce and tighten the sealing rings 200 around theelectrode 250. Each sealing ring 200 is mounted in a ring groove 375 tosecure it in place. In some embodiments, such as the one depicted inFIGS. 4F through 4G, one or more of the ring grooves 375 comprise afurther pressurization groove 376 through which the pressurized air andor inert gases may act upon the sealing rings 200. Pressurization may beachieved by inputting air and/or inert gases into the seal housing 310.The pressure is supplied into the seal housing 310 through the hosefitting 325 and it is passed through the cavities or gas galleries 330in each of the seal housing sections 310 to the sealing rings 200.

In some embodiments depicted in FIGS. 4F through 4G, the cavities, orgas galleries, 330 in the electrode seal assembly 300 may be one ofmachined or cast. The gas galleries 330 are adjacent to the ring grooves375 and allow of air or inert gases to be distributed evenly into theseal housing 310 and surround the sealing rings 200. The pressurized airor inert gases press on the external surface 208 (FIG. 3A) of thesealing rings 200 compressing them around the electrode 250.

FIG. 4G depicts a cross section view of the seal housing 310. Each ringgroove 375 comprises hole inlets 340 through which the pressurized airand or inert gases may be applied to the sealing rings. These holeinlets 340 allow for pressure to be evenly distributed along the outersurface of each sealing ring 200. The ability to control the pressure inthe electrode seal assembly 300 allows for precise electrode feed rate,tighter sealing rings 200, increased system reliability, and ability toincrementally move the electrodes 250 up and down. High pressure allowsthe sealing rings 200 to tightly lock the electrode 250 in place, ifnecessary. Pressurization reduces off-gas. In some embodiments, theoperational range for the air pressure is 5-10 psi but may rise up to20-30 psi. The change in pressure may be maintained with the addition ofmore air or inert gases such that the resulting compression pressure isgreater than the pressure in the vitrification containment system duringoperation.

FIGS. 5A through 5E depict an embodiment of an electrode seal assembly400. FIGS. 5A through 5E utilize a pressure seal similar to the onedepicted and described in FIGS. 4A through 4G.

FIG. 5A depicts an isometric view of the electrode seal assembly 400. Inthe depicted embodiment, the seal housing 410 is split in half in aclamshell design. In some embodiments the seal housing 410 may comprisemore than two portions. In the depicted embodiment, the two halves ofthe seal housing 410 are fastened together with fasteners through holes405. The two pieces of the seal housing 410 clamp around the electrode250 and the sealing rings 200 (FIG. 5B).

FIG. 5B depicts an exploded isometric view of the electrode sealassembly 400. The depicted embodiment comprises the housing seal 410split into two portions, four sealing rings 200, and fasteners (notdepicted). The electrode seal assembly 400 extends into the lid of thevitrification container allowing for a greater overall length of theseal housing 410 which allows for more distance between the sealingrings 200. The extension in length of the seal housing 410 causes moresurface area of the electrode 250 to be sealed and provides moreelectrical insulation between the electrode 250 and the vitrificationcontainer. Additionally, greater distance between the sealing rings 200allows the gap (if present) between electrode 250 segments to passthrough the sealing rings 200 while always maintaining at least oneengaged sealing ring 200. Some embodiments may use more or fewer sealingrings 200. In some embodiments one or more of the sealing rings 200 maybe identical.

FIG. 5C depicts a cross section view of the electrode seal assembly 400.The depicted electrode seal assembly 400 embodiment uses pressurizationto reinforce and tighten the sealing rings 200 around the electrode 250.Each sealing ring 200 is mounted in a ring groove 475 (FIG. 5D) tosecure it in place. In some embodiments one or more ring groove 475(FIG. 5D) may be sized to accommodate one or more sealing rings 200.Pressurization may be achieved by inputting air and/or inert gases intothe seal housing 410. The pressure may be supplied into the seal housing410 through a hose fitting and passed through the cavities or gasgalleries 430 in each of the seal housing sections 410 to the sealingrings 200. The cavities, or gas galleries, 430 in the electrode sealassembly 400 may be one of machined or cast. The vertical gas galleries430 are connected to the ring grooves through holes 420 (FIG. 5D) andallow air or inert gases to flow into the seal housing 410 and surroundthe sealing rings 200. The pressurized air or inert gases press on theexternal surface of the seals compressing them around the electrode 250.

FIG. 5D depicts how air pressure is supplied through holes 420 in thering grooves 475 in the seal housing 410. Each ring groove 475 comprisesholes 440 through which the pressurized air and or inert gases may enterand exit the electrode seal assembly 400. The ability to control thepressure in the electrode seal assembly 400 allows for more preciseelectrode feed rate, tighter sealing rings 200, and increased systemreliability. Higher pressure allows the sealing rings 200 to tightlylock the electrode in place, if necessary. Pressurization reducesoff-gas. The operational range for the air pressure is 5-10 psi but mayrise up to 20-30 psi. The change in pressure may be maintained with theaddition of more air or inert gases such that the resulting compressionpressure is greater than the pressure in the vitrification containmentsystem during operation.

FIG. 5E depicts a bottom view of the electrode seal assembly 400 showingthe vertical gas galleries 430. In the depicted embodiment there aretwenty-two vertical gas galleries. Other embodiments may comprisedifferent amounts of vertical gas galleries 430. In some embodiments,such as the depicted embodiment, the vertical gas galleries 430 areevenly distributed.

FIGS. 6A and 6B depict an embodiment of an electrode seal assembly 500.

FIG. 6A depicts an embodiment of an electrode seal assembly 500comprising top seal housing 520, electrode collar 510, and one or moresealing rings 200. The electrode collar 510 fits over the electrode 250(FIG. 6B) and is partially inserted into the top of the vitrificationcontainer. The electrode collar 510 comprises a flange 511 which restson the top of the vitrification container. Next, graphite sealing rings200 fit over the electrode 250 and rest on top of the electrode collar510. The top seal housing 520 then fits over the sealing rings 200 tocomplete the electrode seal assembly 500. The electrode seal assembly500 may be fastened together and/or to the top of the vitrificationcontainer.

FIG. 6B depicts a cross sectional view of the electrode seal assembly500. One or more fastener holes 505 may be used to fasten the top sealhousing 520 to the electrode collar 510 and to fasten the electrode sealassembly 500 to the top of the vitrification container. The depictedembodiment comprises four sealing rings 200. In some embodiments, suchas the depicted embodiment, the inner sealing rings 200 may be plaingraphite sealing rings and the outer sealing rings 205 may be Inconelwrapped graphite sealing rings 200. In some embodiments the Inconel isspiral wrapped. This embodiment has been tested and confirmed that agood vacuum is maintained.

FIGS. 7A through 7D depict an embodiment of an electrode seal assembly600.

Referring to FIGS. 7A through 7D and starting from the base, a housingseal 650 may be placed between the vitrification container lid and thebottom of the electrode seal assembly 600. The bottom seal housing 620is flanged, with the flange resting atop the housing seal 650 and therest of the bottom seal housing 620 is inserted into the top of thevitrification container. A bolt hub 610 may connect to the bottom of thebottom seal housing 620, with a bolt hub gasket 625 in between in someembodiments, to fasten the electrode seal assembly 600 together. A firstsealing ring 200 is held in place by the bolt hub 610 against the bottomof the bottom seal housing 620. A second sealing ring 200 fits into agroove in the top of the bottom seal housing 620. A ring 630 fitsbetween the second sealing ring 200 and a third sealing ring 200. Thetop seal housing 605 fits over the second and third sealing rings 200and the ring 630.

One or more housing gaskets 655 may be placed between the top of thebottom seal housing 620 and the top seal housing 605. The depictedembodiment comprises three housing gaskets. The outer two housinggaskets 653 may be composed graphite. The center housing gasket 655 maybe composed of metal, such as stainless steel, sandwiched between layersof graphite in some embodiments. The number and composition of housinggaskets 655 may vary in different embodiments. A fourth sealing ring 200fits on top of the top seal housing 605 and is held in position by abolt hub 610. A bolt hub gasket 625 may be placed between the bolt hub610 and the top seal housing 605. Fasteners, such as bolts, may extendthrough the electrode seal assembly 600 to fasten the componentstogether. In some embodiments, one or more of the top seal housing 605,bottom seal housing 620, bolt hubs 610, and ring 630 may be comprised ofceramic material or other materials.

Process and Control

FIGS. 8A through 8F depict an embodiment of a Vitrification (FIG. 8A)and Off-Gas Treatment (FIGS. 8B-8F) control system. In the figures longbold dash lines (FIG. 8A) indicate frit feed, double lines (FIGS. 8A and8B) indicate air, bold lines (FIGS. 8A-8B and 8D-8F) indicate off-gas,medium lines with small arrowheads (FIGS. 8B-8D) indicate waterincluding scrub water (FIGS. 8A-8B), short dashed lines (FIG. 8C)indicate glycol, dotted lines (FIG. 8D) indicate pH adjustmentchemicals, and thick dashed lines (FIGS. 8A-8E) indicate electrical andor control signals.

FIG. 8A depicts an embodiment of a vitrification system (Zone 1). Thevitrification container may comprise one or more layers of insulatingmaterials. The depicted embodiment comprises cast refractory and silicasand. Frit, which may comprise glass formers in some embodiments, may befed into the top of the vitrification container through one or morepressure control valves. In the depicted embodiment two pressure controlvalves PCV-102 and PCV-103 have feed while melt (FWM) airlock controls.The FWM airlock controls allow additional materials to be fed into thevitrification container as the preloaded material volume is reducedduring the vitrification process. The airlock provides an air seal intothe plenum area such that there is no open route for plenum air to leakinto the environment. The feed point is connected to a heat shield andheat shield level control. The electrodes may be fed into thevitrification container through electrode level controls and electrodeseal assemblies.

The depicted process embodiment is powered by a three phase utilityinput into a power transformer (a Scott-T power transformer in thedepicted embodiment). The power transformer may allow minimal operatorinterface to accomplish the purpose of initiating and providing theheating mechanism for a vitrification process. Output out of the powertransformer may initially be controlled by an operator input program togradually increase power to the Vitrification Zone in the vitrificationcontainer.

Currently, the vitrification process is controlled manually. The abilityto control the process with little to no manual input could increaseprocess efficiency and reduce necessary processing time as well asremove possibility of human error. Programmed inputs may be utilized toinitially control the power ramp up to initiate the melting process. Asoftware program may be linked to the existing process control system togradually increase the power output of the transformer on a predefinedschedule (timeline) up to a nominal operating level. The continuedoperation of the system beyond that point may then use logic based oninput from temperature, pressure, visual (e.g. infrared) and or othersensory inputs to adjust the power input to the desired level to safelyand efficiently operate the process. Power control may run in parallelwith other system control logic that manages off-gas flow, hood vacuum,differential pressures, and other variables throughout the system. Thecontrol system may be utilized for both sub-surface Planar™ (in-situapproach) and in container vitrification, ICV™, technologies as well asother vitrification systems and methods.

In Zone 1, plenum sweep air is introduced through line 2 through apressure control valve PCV-101 and further through a filter (HEPA in thedepicted embodiment). The plenum sweep air is used to remove water vaporand gases generated during vitrification from the off-gas hood and routethem into off-gas treatment system for treatment before releasing thetreated off-gas to the environment. In some embodiments, the removedcontaminants may be processed and or stored separately.

With reference to FIG. 8B, the off-gas enters Zone 2 through line 4. Itmay be joined by balance air which is introduced through a pressurecontrol valve PCV-201 and further through a filter (HEPA in the depictedembodiment). The off-gas (mixed with balance air in some embodiments)then may proceed through at least one filter. In some embodiments two ormore filters are in parallel. In some embodiments having parallelfilters, flow travels through more than one filter at a time. In someembodiments having parallel filters, flow only travels through onefilter at a time and is controlled by valves.

In the depicted embodiment, the flow may travel through valve HV-201into a sintered metal filter (SMF) and out through valve HV-202.Alternatively, flow may be directed through valve HV-203 into a HEPAfilter and out through valve HV-204. From either valve HV-202 and orvalve HV-204 flow travels into Zone 4. A water (or other cleaning fluid)rinse may be provided through valve HV-207 to periodically rinsecaptured contaminants from the SMF filter.

Air, or fluids, may be introduced through valve HV-205 into a backpulseair reservoir through valve HV-206 into the SMF. The backpulse air mayflow out of the SMF through valve HV-208 to backpulse air recycle. Thebackpulse air is used to clean the SMF. The backpulse air quickly blowsbackwards into the SMF to knock particulate off of the filter whichallows it to drop to the bottom of the filter housing where it iscollected and can be fed back into the vitrification container forprocessing. In some embodiments, the filter housing may comprise morethan one filter wherein each filter is backpulsed at different timeswith small individual pulses so as not to pressurize the off-gas systemwith a single large backpulse.

Some embodiments may include an optional Zone 3, depicted in FIG. 8C,for cooling the water in Zone 4 (FIG. 8D). In other embodiments Zone 3is not optional and is a requirement. Glycol travels in a circuitthrough a glycol cooler to a first heat exchanger (HX-1), from thebottom of HX-1 through a pump, into the base of a second heat exchanger(HX-2), and back to the glycol cooler. Water flows through heatexchangers HX-1 and HX-2 and back to Zone 4 (FIG. 8D).

In the depicted embodiment the off-gas travels from Zone 2 into tandemVenturi scrubbers and through a mist eliminator into Zone 5 as shown inFIG. 8E. Other embodiments may utilize different scrub systems includingdry scrubbers, electrostatic precipitators, and the like. The tandemVenturi scrubbers are situated in proximity to a scrub tank. Fresh watermay be fed into the scrub tank through valve HV-410. Water exits thescrub tank and goes through valve HV-403 to a scrub pump. Optionally,water may be discharged from valve HV-412. The scrub pump pumps thewater through valve HV-404 and HV-405 into particulate scrub filter.Alternatively, the flow may bypass the particulate scrub filter throughvalve HV-409. Water may drain from the particulate scrub filter throughvalve HV-406. Off-gas may vent from the particulate scrub filter throughvalve HV-408. The water exiting the particulate scrub filter throughvalve HV-407 and travels through valves HV-401 and HV-402 into tandemVenturi scrubbers. In some embodiments the water may also travel throughvalve HV-411 into the scrub tank. In some embodiments, the pH of thewater in the scrub tank is adjusted with a pH adjusting chemical that isfed from a chemical (pH) buffer tank through chemical pump and throughvalve HV-413.

The scrubbed and filtered off-gas from Zone 4 (FIG. 8D) may travelthrough a heater and through one or more filters in series. In thedepicted embodiment the heated off-gas travels through valve HV-501 intoa first filter through valves HV-502 and HV-504 through another filterand valve HV-505 to Zone 6 (FIG. 8F). Alternatively, one or more of thefilters may be bypassed by passing the off-gas through valves HV-503 andor HV-506. In some embodiments one or more filters may be situated inparallel where they may be used in conjunction with the primary filtersor as an alternative to the primary filters.

The off-gas from Zone 5 travels through valve HV-601 through primaryblower and is discharged from a stack outlet. Alternatively, the off-gasmay flow through valve HV-602 into secondary blower and through valveHV-603 to be discharged through the stack outlet.

Other Process Embodiments

Various filter types are contemplated including, but not limited to,HEPA, SMF, and HEGA. Various valve types are contemplated. Valves mayvary from the depicted process diagrams for differing flow rates andvolumes and other design considerations. Additional valves, such ascheck valves, may be positioned throughout the system to prevent fluidsfrom traveling in the wrong direction. Other valves, including automaticmotor operated valves or redundant valves, may be included a variouspoints in the process to provide increased factor of safety.

Sensors

One or more sensors and instruments may be used to monitor and controlsystem properties throughout the process. In the embodiment of FIGS.8A-8F, several instruments and/or sensors are included in each zone.Other embodiments may include more or fewer sensors and/or instrumentsin other positions throughout the system. The positions and types ofsensors and/or instruments may be dependent upon the scale of theprocess as well as the chemical properties of the off-gas, among otherdesign considerations. Types of sensors may comprise one or more ofcontact sensors, non-contact sensors, capacitive sensors, inductivesensors, 3D imagers, cameras, thermal imagers, thermometers, pressuresensors, radiation detectors, LIDAR, microphones, among others.

Some embodiments may comprise one or more imaging sensors. The one ormore imaging sensors may comprise one or more of 3D imaging, 2D rangesensor, camera, thermal imager, and radiation detector, among others.One or more imaging sensors may be used to provide inspection andmonitoring capabilities for remote operators. Signals from one or moreimaging sensors may be displayed in real-time, recorded for laterreview, and/or recorded for operational records. Any one or more of thecameras may be one of fixed or pan-tilt-zoom types. An operator mayselect and manage desired camera views for operations, while controllingthe cameras with associated control features such as the pan, tilt, zoom(PTZ), focus, and lights. In an embodiment, proper visual coverage ofoperations may be made possible by a camera system through adequatecamera coverage, determined by camera quantity and location.

In some embodiments sensors are added merely for tracking of theproperties of the materials throughout the process. In some embodimentssensor data is used to control the operation of the system. Someembodiments may utilize sensor fusion algorithms to analyze dataretrieved from one or more sensors of one or more different types. Insome embodiments, the sensor data will automatically be analyzed andautomatically effect changes in the control system for the processrequiring little to no input from a human operator. In some embodiments,the sensor data and or analysis is displayed for a human operator toperform manual adjustments.

In the depicted embodiment, Zone 1 (FIG. 8A) comprises nineteeninstruments. In the depicted embodiment, fifteen temperature indicatorsare used to monitor the temperature of the vitrification container:TI-101 through TI-106 monitor incremental depths of the material in thevitrification container, TI-107 monitors the northeast (NE) corner sand,TI-108 monitors the southeast (SE) corner sand, TI-109 monitors thesouthwest (SW) corner sand, TI-110 monitors the northwest (NW) cornersand, TI-111 monitors the inner sand, TI-112 monitors the middle sand,TI-113 monitors the outer sand, TI-114 monitors the outer skin, andTI-115 monitors the bottom skin. Additional temperature indicators maybe used to monitor the temperature at other various locations. In thedepicted embodiment, further temperature indicating transmitters TI-116,TI-117, and TI-118 are used to monitor temperature at the electrodeseal, the infrared (IR) video camera, and in the top of thevitrification container, respectively. A pressure indicating transmittermay be used to monitor the pressure within the vitrification container.

In the depicted embodiment, Zone 2 (FIG. 8B) comprises five instruments.A pressure differential indicating transmitter, PDIT-201, is used todetermine and transmit the pressure differential before and after theSMF and or HEPA filter. Flow indicating transmitter FIT-201 andtemperature indicator TI-201 are used to monitor the balance air input.The temperature of the off-gas is monitored by temperature indicatorTI-202 just before the filters and just after the balance air is added.

In the depicted embodiment, Zone 4 (FIG. 8D) comprises fourteeninstruments. A flow indicating transmitter FIT-401 and a temperatureindicator TI-401 are used to monitor the properties of the off-gasentering Zone 4. Pressure differential indicating transmitters PDIT-401and PDIT-402 are used to monitor the differential pressure of theoff-gas just before and after the tandem venture scrubbers and justbefore and after the mist eliminator, respectively. Pressure indicatingtransmitters PIT-401 and PIT-402 monitor the pressure of the water justbefore the first and second tandem Venturi scrubbers, respectively.Temperature indicator TI-402, level indicating transmitter LIT-401, andpressure indicating transmitter PIT-403 are used to monitor the scrubtank. Temperature indicator TI-403, pressure indicating transmitterPIT-404, and flow indicating transmitter FIT-402 are used to monitor thewater downstream of the scrub pump. Pressure differential indicatingtransmitter PDIT-403 monitors the differential pressure in the waterbefore and after the particulate scrub filter. Analyzer indicatingtransmitter AIT-401 connects to the scrub tank and variable frequencydrive (VFD) at the chemical pump and is used to monitor the pH and feedsthe pump to add caustic to the scrub tank.

In the depicted embodiment, Zone 5 (FIG. 8E) comprises five instruments.Pressure differential indicating transmitters PDIT-501 and PDIT-502 areused to monitor the differential pressure before and after a first andsecond filter, respectively. Temperature indicators TI-501, TI-502, andTI-503 monitor the temperature of the off-gas entering Zone 5, betweenthe heater and the first filter, and after the filters, respectively.

In the depicted embodiment, Zone 6 (FIG. 8F) comprises four instruments.Temperature indicators TI-601 and TI-602 monitor the temperature of theoff-gas entering Zone 6 and discharge, respectively. Pressure indicatingtransmitter PIT-601 monitors the pressure of the off-gas prior to entryto the blower. Flow control transmitter FCT-601 monitors and controlsflow generated by the primary blower with variable frequency drive.FCT-601 is connected to the off-gas hood pressure indicating transmitterPIT-101 in Zone 1. As the vacuum in the hood drops the blower is sped upto increase flow and vacuum.

For the sake of convenience, the operations are described as variousinterconnected functional blocks or distinct software modules. This isnot necessary, however, and there may be cases where these functionalblocks or modules are equivalently aggregated into a single logicdevice, program or operation with unclear boundaries. In any event, thefunctional blocks and software modules or described features can beimplemented by themselves, or in combination with other operations ineither hardware or software.

Having described and illustrated the principles of the systems, methods,processes, and/or apparatuses disclosed herein in a preferred embodimentthereof, it should be apparent that the systems, methods, processes,and/or apparatuses may be modified in arrangement and detail withoutdeparting from such principles. Claim is made to all modifications andvariation coming within the spirit and scope of the following claims.

The embodiments in which an exclusive property or privilege is claimedare defined as follows:
 1. An electrode seal assembly for mounting anelectrode with respect to a vitrification container, the electrode sealassembly comprising: a housing extending around the electrode when theelectrode is inserted through the housing, the housing having; a firsthousing section, a second housing section coupled to the first housingsection, at least one fastener fastening the first and second housingsections together, two or more annular ring grooves recessed into thehousing, and a sealing ring received within each of the two or more ringgrooves, wherein an external face of each sealing ring is recessed intoa respective one of the ring grooves, and wherein an internal face ofeach sealing ring is positioned to engage and seal against the electrodewhen the electrode is inserted through the housing.
 2. The electrodeseal assembly of claim 1, wherein the first and second housing sectionsdefine portions of the housing cooperating to surround the electrodewhen the electrode is inserted through the housing.
 3. The electrodeseal assembly of claim 1, wherein the first and second housing sectionsare located at different positions along the electrode.
 4. The electrodeseal assembly of claim 1, wherein the at least one fastener is a bolt.5. The electrode seal assembly of claim 1, wherein the at least onefastener is positioned to connect the electrode seal assembly to thevitrification container.
 6. The electrode seal assembly of claim 1,further comprising a seal between the first and second housing sections.7. The electrode seal assembly of claim 1, further comprising a sealpositioned on an exterior surface of the second housing section to sealthe housing against the vitrification container.
 8. The electrode sealassembly of claim 1, wherein the sealing rings are movable to tightenthe sealing rings around the electrode when the electrode is insertedthrough the housing.
 9. The electrode seal assembly of claim 1, furthercomprising holes defined in the housing through which the ring groovesare pressurized.
 10. The electrode seal assembly of claim 1, wherein thefirst housing section has an annular flange by which the first housingsection is fastened to the second housing section.
 11. The electrodeseal assemblies of claim 1, wherein the first and second housingsections each have an annular flange by which the first and secondhousing sections are fastened together.
 12. The electrode seal assemblyof claim 1, wherein the flange extends outward for being supported uponthe vitrification container.
 13. The electrode seal assembly of claim 1,wherein the first and second housing sections cooperate to define one ofthe ring grooves.
 14. A method of sealing an electrode with respect to avitrification container, the method comprising: inserting a firstsealing ring into a first annular ring groove defined in an innersurface of a housing; inserting a second sealing ring into a secondannular ring groove defined the inner surface of the housing; fasteninga first section of the housing to a second section of the housing todefine a passageway through the housing; receiving the electrode in thepassageway; engaging the first sealing ring against the electrode at afirst location along the electrode; engaging the second sealing ringagainst the electrode at a second location along the electrode; sealingthe first sealing ring against the electrode at the first location;sealing the second sealing ring against the electrode at the secondlocation.
 15. The method of sealing an electrode as claimed in claim 14,wherein the first annular groove is defined in both the first and secondsections of the housing.
 16. The method of sealing an electrode asclaimed in claim 14, wherein the first annular groove is defined by boththe first and second sections of the housing.
 17. The method of sealingan electrode as claimed in claim 14, further comprising: fastening thehousing to the vitrification container; and sealing the housing againsta surface of the vitrification container.
 18. The method of sealing anelectrode as claimed in claim 17, wherein fastening the first section ofthe housing to the second section of the housing, and fastening thehousing to the vitrification container are performed by the samefastener.
 19. The method of sealing an electrode as claimed in claim 14,further comprising sealing the first section of the housing to thesecond section of the housing with a seal.
 20. The method of sealing anelectrode as claimed in claim 14, further comprising tightening thesealing rings against an exterior surface of the electrode.